It is not the greatest holder, but it's simple and it will hold one 2.5" (SSD) and three 3.5" HDDs. No screws required, loosely/friction fit, it's easy from this setup to swap HDDs very quickly. Suiting for open cases/setups. And cooling of HHDs is much better, because in a horizontal position they needed spacers and some draft/fan passing air through so the bottom HDDs will not cook the top HDDs. No support required for printing.